1. Field of the Invention
The present invention relates to a light-emitting diode illumination apparatus, and more particularly, relates to a light-emitting diode illumination apparatus having a heat pipe with different section areas.
2. Description of the Prior Art
With the development of semi-conductor light emitting devices, a light-emitting diode (LED) becomes a new light source. It has several advantages, for example, saving power, seismic resistance, being short in reaction time, being proper in mass production and so on. Therefore, LEDs are widely used as indicator lights and it is a trend to use LEDs as a light source of illumination products.
LEDs as a light source have to provide enough illumination. It means it is necessary to use a lot of low-power LEDs or to use a small number of high-power LEDs. When a lot of low-power LEDs are used as a light source, it can reduce the requirement of unit heat-dissipating efficiency, so as to reduce the requirement of heat-dissipating devices but increase the total volume thereof. Therefore, using a lot of low-power LEDs as a light source is not applicable to illuminating.
Additionally, high-power LEDs as a light source have to be equipped with a heat-dissipating device having a high heat-dissipating efficiency. The heat-dissipating device of the prior art usually carries a small number of high power light-emitting diode modules merely, so that the illumination is not enough especially for road lighting. Therefore, in the prior art, an independent high-power LED is equipped with its own heat-dissipating device and a few of the independent high-power LEDs are combined together to provide enough illumination. The volume of the above-mentioned structure is not small enough and the applications of the structure may be confined thereby.
Additionally, if a metal plate is used to carry several light-emitting diode modules and one or more heat pipes are inserted through the metal plate to indirectly conduct the heat generated by the light-emitting diode module in operation, the heat-conducting efficiency of the metal plate is lower than the heat-conducting efficiency of the heat pipes. Thereby the metal plate is a bottleneck of the whole heat-dissipating mechanism. Therefore, this kind of structure does not satisfy with the requirement of high heat-dissipating, for example, road lighting.
Moreover, even if a vapor chamber replaces the metal plates, the heat conducted by the vapor chamber still has to be taken away by other methods. It may use other heat pipes to touch the vapor chamber, so that the heat could be conducted from the vapor chamber to the heat pipes. Perhaps one or more heat-dissipating fan is set on the vapor chamber to dissipate the heat. For the former, because the touched area is a bottleneck of the heat-dissipating, the heat-dissipating efficiency is limited thereby. For the later, the volume of the whole apparatus is huge and the variability of the structure is smaller; for example, the heat-dissipating fan has to be set on the vapor chamber directly for dissipating heat effectively. Additionally, the later still needs extra energy to drive the heat-dissipating fan and the heat-dissipating fan is not suitable to be exposed outdoors in order to obtain a higher heat-dissipating efficiency.
Therefore, a scope of the present invention is to provide a light-emitting diode illumination apparatus having a heat pipe with different section areas. The heat pipe has a flat end where one diode light-emitting module with a bigger heating area or several diode light-emitting modules could be carried. The light-emitting diode illumination apparatus could dissipate heat directly and rapidly for solving the above-mentioned problems.